1. Field of the Invention
This invention relates to artificially-colored, translucent substrates and a process for their manufacture. In a preferred embodiment, the substrates are foodstuffs.
2. The Prior Art
It is difficult to think of a product which does not contain artificial coloring or dyes. Most commonly, these colorings or dyes are monomeric chromophoric chemical species. There has been, however, substantial effort devoted to dyes and colorings which are polymeric. These materials have found application in textile dyeing, as evidenced by U.S. Pat. No. 3,232,691, granted Feb. 1, 1966 to Wilhelm et al; photography, as evidenced by U.S. Pat. No. 3,073,699, granted Jan. 15, 1963 to Firestine; dyeing of cellulose derivatives, as evidenced by U.S. Pat. No. 2,371,052, granted Mar. 6, 1945 to Kirby; and in coloring foods, as evidenced by the article "Studies on Polymeric Dyes I, Macromolecularization of Food Dyes" by Ida et al, appearing at pages 517-523 of Volume 89 (1969) of Yakugaku Zasshi.
Polymeric dyes and colors do not contain pure chromophore. Instead, they additionally contain nonchromophoric units, chemical groups and/or molecular segments which function to bind the chromophoric groups into a polymeric form. It is therefore quite understandable that, on a pound for pound basis, in most applications polymeric dyes are somewhat less potent colorants than monomeric dyes.